The principle for retrenchment (commonly in private sector)

LIFO (last-in, first-out)(last come, first go)

In effecting retrenchment, an employer should comply with the principle of LIFO

--(See Syarikat Osborne & Chappel Sdn. Bhd. v. Kesatuan Kakitangan Perusahaan Lombong [ I.C. Award No. 9/71]),

unless there are sound and valid reasons for not doing so, eg.

a.    Specialize/expert worker

b.    Key personnel (witout him/her the company/operation will be shut down), and then other methods applies:

LILO (last in, last out);
FILO (first in, last out); and
FIFO (first in, first out)